This means that when the doctor gets the test report back, and they look for results flagged as abnormal, anything between .5 and 5.0 will not be flagged.
Doctors who don't know about the new guidelines, and rely on the flagging of results by the lab as high/low/abnormal, are not practicing according to the new recommended guidelines.
In other cases, doctors have deliberately chosen not to follow the recommended new guidelines. These doctors will not diagnose hyperthyroidism in people with TSH levels between 0.3 and 0.5 -- and also will not diagnose hypothyroidism in the many millions of Americans with a TSH level of 3.0 to 5.0.
This means that being told your TSH test is "normal" doesn't really mean anything... because you can have a TSH anywhere from .3 to 5.0, and be told your test is normal. You can have a TSH of 4.0, and be told by one doctor that you are normal, and by another that you are hypothyroid and require treatment.
